AMD 690G boosts laptop battery life

RS690 HAS A FEW TRICKS UP ITS sleeve to help with mobile power consumption, we found out recently. The tweaks help to give DAAMIT-based laptops a bit of a boost over the next few months, which they're going to seriously need as Merom ramps and the Santa Rosa platform is launched.

Earlier, we had reported that one version of the chipset supported an external frame buffer of dedicated graphics RAM for increased performance, but now it's emerged that the performance boost isn't that huge.

Instead, the main point is that the K8, with its on-die north bridge, cannot go into a proper sleep mode when idle as a shared memory graphics controller needs to continuously access the memory. With the RS690T, this is no longer a problem as it can use the local store and let the CPU drop into the lower power state.

The next neat trick is something that this hack's Sony laptop half-heartedly implements. When you're doing 90% of your work, then the chances are you do not need lightning fast 3D performance, so integrated graphics is fine - especially if it can cope with Vista's Aero Glass malarkey, if that's your bag. And it will use a lot less power. However, try to play a reasonably modern game, then you're going to be watching a slideshow.

The Sony SZ series deals with this by using a 945GM for normal office type usage, and a mobile GeForce 7300 for 3D work. Still not top of the range, but good enough for CAD and a bit of casual gaming. However the snag is that you need to power down the PC and move a switch to select between the two then reboot, which limits its usefulness somewhat.

The RS690 series allows you to hot swap without rebooting between an external GPU and the built in X1250 core, which is still no real slouch, but this way you can choose between better battery life and the ability to play some games properly, which sounds like a good solution to us.

At the very least, we're glad to see the approach of considering the chipset and overall system power consumption much more these days, rather than just the CPU, which is a pleasant change from the runaway TDPs of Intel's mobile chipsets. µ

See Also
RS690T to have external graphics RAM
965GM is considerably hotter than its predecessors